Growth factors are naturally occurring substances, usually proteins, that act as signaling molecules between cells. Their primary function is promoting cell differentiation and maturation. They play an important role in stimulating cell growth, proliferation, and wound healing. Many large classes, or superfamilies, of related growth factors are known.
Growth Differentiation Factor 11 (GDF11) is a protein belonging to the transforming growth factor (TGF) superfamily. Blood-derived GDF11 was recently shown to be involved in reverting aging phenotype in mice, including cardiac hypertrophy (see Loffredo et al., Cell, 2013, 153, 828-839), age-related sarcopenia (see Sinha et al., Science, 2014, 344:649-52), and decreased cognitive functions (see Villeda et al., Nat. Med. 2014; 20:659-63). Transforming growth factor beta (TGFβ) is another member of the TGF family. It controls proliferation, cellular differentiation, and other functions in most cells. Connective tissue growth factor (CTGF) is a protein of the CCN family of extracellular matrix-associated heparin-binding proteins. CTGF has important roles in many biological processes, including cell adhesion, migration, proliferation, angiogenesis, skeletal development, and tissue wound repair. It is thought that CTGF can cooperate with TGFβ, although the pathways remain largely unknown. Finally, platelet-derived growth factor (PDGF) is known to play a significant role in angiogenesis, the growth of blood vessels from already-existing blood vessel tissue.
Due to the many important roles growth factors play in maintaining healthy tissues, there has been some interest in using them in dermatological formulations. There are, however, drawbacks associated with the use of growth factors in topical formulations.
It is therefore an object of the invention to provide new peptides, derived from growth factors, and topical compositions containing them. It is also an object of the invention to provide methods for improving the health and/or appearance of skin, combatting signs of intrinsic and photoaging, and/or treating skin disorders. It is a further object of the invention to provide compositions and methods for treating, reversing, forestalling and/or ameliorating skin wrinkles and fine lines with cosmetic compositions comprising effective amounts of a peptide of the invention.
The foregoing discussion is presented solely to provide a better understanding of the nature of the problems confronting the art and should not be construed in any way as an admission as to prior art.